Lighting devices that emit white light can be achieved, for example, by the combination of one or a plurality of red-emitting LEDs with one or a plurality of so-called conversion LEDs, which generate blue light which is converted into light having a different wavelength, for example greenish-white light, in a conversion layer. The respective operating current of the LEDs used is adapted in such a way that the superimposition of the light emitted by all the LEDs produces white light on the white curve of a Planckian black-body radiator.
What is problematic in the operation of the lighting device is the different temperature behavior and aging behavior of the red-emitting and greenish-white-emitting LEDs, which has the consequence that the color locus of the lighting device is difficult to stabilize on account of the temperature dependence.